Bump mercurius from 14.1.0 to 15.0.0

Bumps [mercurius](https://github.com/mercurius-js/mercurius) from 14.1.0 to 15.0.0.
- [Release notes](https://github.com/mercurius-js/mercurius/releases)
- [Commits](mercurius-js/mercurius@v14.1.0...v15.0.0)

---
updated-dependencies:
- dependency-name: mercurius
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -44,7 +44,7 @@
     "autocannon": "^7.15.0",
     "concurrently": "^9.0.0",
     "fastify": "^4.26.2",
-    "mercurius": "^14.0.0",
+    "mercurius": "^15.0.0",
     "pre-commit": "^1.2.2",
     "snazzy": "^9.0.0",
     "standard": "^17.1.0",